Guidelines for Repacking a TB Exhaust Canister

by Henrik Morkner

vfr

This article was written by Henrik Morkner, posted on the VFR List and he has graciously allowed me to post it here. I think it is offers guidance to anyone wanting to repack any exhaust canister. In fact, it helped me to re-pack my D&D.
I just repacked my TBR C2 cf can on my '95 since it was at 12K miles. The procedure is straight forward with a little help (thanks Chris Salazar).
  1. Remove the can from the bike (simple, just unbolt bracket, pull springs).

  2. Use a variable speed drill and pick a drill size slightly bigger than the rivets that circle the two (2) ends of the can.

  3. Slowly drill out the rivets. Start with the back end since it's not connected to the center tube. Once the top of the rivet comes free then stop since the bottom half of the rivet will simply fall out later when it's apart.

  4. Remove all the rivets on both ends (NOT length wise though). Pull the end cap off then gently twist and turn the cf shell until it slips off.

  5. Look for burned through areas of the existing packing. The stuff use at TBR is pretty good quality stuff. Mine had no obvious burned through areas. As I began to unwrap it, the forward-top portion had a golf ball size pocket forming that would have gone all the way through in a few more miles by my guess.

  6. Remove all the old packing and clean the center tube, cf shell, and the ends.

  7. Replace the packing with loose or sheet type packing. I was told by the shop that the loose, ceramic packing was the best, so that's what I bought. However, the fiberglass stuff that comes in 1" thick sheets is probably easier to install and is more like the OEM. BTW the TBR C2 cf took 1.5 bags of the stuff since it's bigger than most.

  8. Carefully wrap the ceramic packing around the bare center tube to the approximate size of the cf shell. I used some string to hold it together (just till you get the can shell back on).

  9. Slip the cf can over the center tube and packing. Then I took more packing and carefully put it in layer by layer while pushing it down gently with a rod and shaking the whole can.

  10. Put the end cap back on and I used a standard Stanley rivet gun to replace the rivets. I used aluminum rivets since their are easier to squish and the cf is brittle and could be crushed by the steel ones.

  11. Re-mount the canister and power-up. I noticed that my pipe has a slightly lower, baritone sound with the ceramic packing as opposed to the fiberglass.
Available from TBR - a repack kit #005-10038.

Good Luck
-Henrik '95 VFR750FS Palo Alto, CA


An Additional Comment by David M. Matthew '91 VFR750F-(RC36)

Alloy or CF silencers that use "glass pack" style mufflers (canisters) need repacking at some point. Some OME canisters/silencers use metal baffles and do not therefore need re-packing as there is nothing to pack... and no way of accessing the innards anyway.

Special Addendum by Rob McKinnon

First off, fibreglass packing is at least a pain. Doesn't last long enough no matter who sells it to you. I tried fibreglass in the Yosh slip-ons on my '86 vfr for 5 or 6 seasons and had to repack every year.

Then I discovered "SUPERWOOL 607". It is an industrial insulation for hi-temp applications such as turbocharger blankets on large gas compressors (2000+ HP). It is also used to wrap steel pipe prior to stress-relieving weld joints. It is a "Refractory Ceramic Fiber product" made from "Crystalline silica formed at over 1800' F', according to the manufacturer. It comes in a bulk blanket form, about 1.25 inches thick, which I cut to size easily with ordinary household scissors.

This stuff does not burn out period. I have a small plastic grocery bag full and have only repacked the "old' vfr mufflers twice in 8 years. Once the first time and once when I had the pipes disassembled for nickel plating and polishing the canisters. Even then, the packing was in great shape physically, just dirty is all.

If you can contact some industrial (oilfield) insulators or (pipe) stress relievers locally, they should have it in stock. If not, here is the manufacturers information: Thermal Ceramics, Agusta Ga. at 800-722-5681.

They will probably give you a line about it not being meant for this application. Well they are right, it isn't. In fact it is far superior to anything you will ever find.

NOW FOR THE SAFETY WARNING!

IT IS A SUSPECTED CARCINOGEN AND SHOULD BE HANDLED WITH A MASK AND GLOVES, WASH CLOTHING AFTERWARD. Again this is from the manufacturer's label and I assume no responsibility for anything at all. You are on your own!

That being said, SUPERWOOL 607 will be the last packing you will buy. Period. It works for me. And No, I cannot get you any. I had to ask someone nicely for my tiny stash and I expect it to last at least 20 years or more at the rate it's going!

Hope this helps.


Special Addendum by Greg Leach

I have some info that may help some of the DIY people. The report on repacking exhaust cans tells of a permanent packing material called superwool, but does not tell where to get the stuff. Superwool goes by various trade names, but is essentially a flame (heat) proof space-industry spin off that looks like a 1" thick roll of white cotton. This material comes in 24" wide rolls, and sells for about $2.50 a square foot. Most applications need 2 square feet. This material can be found at any store that sells ceramic/pottery supplies like clay, glaze, and kilns. Do wear gloves and a mask when handling it because it does contain fibres that will easily embed in your hands or lungs. I hope this helps, and feel free to edit as needed.

Greg Leach, 95 VFR


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